Quakes are not an exclusive phenomenon of our planet. Other worlds in the Solar System shake due to their internal processes. The Moon has been known to have moonquakes for decades and just this year, marsquakes were detected on the Red Planet by NASA’s InSight mission.
So far, the InSight lander has detected around two quakes a day and researchers have been able to trace the biggest ones to their source, a region known as Cerberus Fossae located about 1,600 kilometers (1,000 miles) east of InSight. Previous observations of the area showed all the visual hallmarks of a fault system, and now these suspicions have been confirmed by data. The region is definitely active.
The quakes were detected on sol 173 (May 23, 2019) and sol 235 (July 27, 2019), the 173rd and 235th Martian days of the mission. They had a magnitude of between 3 and 4 – similar events on Earth would at most shake tall buildings and parked cars. But on Mars, since there are no tectonic plates, quakes of this size are quite significant.
The cause of these marsquakes is not perfectly clear. InSight’s job is to provide data so that models of the Martian interior can be improved. Build-ups of stress along geological faults are a likely cause for the sol 173 and 235 marsquakes.
The team hopes that in the future, these measurements can be combined with satellite observations of the region. Quakes such as these can cause boulders to shift and can even produce landslides. Researchers hope to find evidence of this by comparing recent and future high-resolution observations. If this approach is successful, the team will hopefully be able to better pinpoint the epicenters of the quakes, refine models, and provide new clues about the exact cause of the tremors.
The findings were presented a few weeks ago at the American Geophysical Union meeting in San Francisco and were first reported on by National Geographic. The study is currently being peer-reviewed but is expected to be published very soon.
The paper will deliver a lot more detail on the structure of the quakes, providing information beyond just their magnitude and the fact that both primary and secondary seismic waves were detected. Just 13 months after its touchdown on Mars, InSight is opening an incredible new window into this unique planet.